# CVE-2026-52720: Gstreamer1-plugins-bad-free: gstreamer: heap buffer overflow via crafted vnc server rectangle in librfb

> A heap buffer overflow in GStreamer's librfb allows remote code execution or crashes via a malicious VNC server.

- **Severity:** High 8.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 15 Jun 2026
- **Updated:** 3 Aug 2026
- **Also known as:** DEBIAN-CVE-2026-52720, ECHO-08db-101f-0369, GHSA-38vh-57p3-w3gw, UBUNTU-CVE-2026-52720

## What is CVE-2026-52720?

CVE-2026-52720 is a high-severity memory corruption vulnerability in Red Hat Enterprise Linux 10, published on 15 Jun 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

A heap buffer overflow vulnerability was found in GStreamer's librfb (RFB/VNC client). The rectangle bounds check incorrectly validates area rather than individual dimensions, allowing a malicious VNC server to send a rectangle that extends beyond the framebuffer. A remote attacker could set up a malicious VNC server and trick a user into connecting, resulting in an out-of-bounds heap write that could lead to code execution or a crash.

Weakness: CWE-122 (Heap-based Buffer Overflow)

## Which versions are affected by CVE-2026-52720?


## How do I fix CVE-2026-52720?

Apply the vendor's patch.

## Is CVE-2026-52720 being exploited?

There is no known exploitation of CVE-2026-52720 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-52720 and fix it if it is affected.

What it is: CVE-2026-52720 is a high-severity memory corruption vulnerability in Red Hat Enterprise Linux 10, published on 15 Jun 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-52720 in the wild and no public exploit code.

Affected product: Red Hat Enterprise Linux 10. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-52720/ (Markdown: https://insights.sbomify.com/CVE-2026-52720/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-52720
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-52720
- OSV: https://osv.dev/vulnerability/CVE-2026-52720

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-52720/
Summaries are generated and may contain mistakes; the official description above is the record.